Passive killer 'proof'

An international team of 29 experts analysed more than 3,000 studies to confirm what has long been maintained by doctors and health campaign groups.

The same team also found that tobacco can trigger cancer in areas of the body not previously linked to smoking - meaning that those hooked on cigarettes are at an even greater risk of contracting the disease than previously feared.

The incontestable verdict on passive smoking was delivered by the International Agency for Research on Cancer, which is part of the World Health Organisation.

Their findings show that nonsmokers exposed to second hand smoke face an increased risk of 20-30 per cent of developing cancer.

Sir Richard Doll, whose research 50 years ago in the UK first linked smoking to lung cancer, and a member of the IARC group, said hundreds of thousands more cases of the disease worldwide could now be attributed to smoking.

'It is the first time there has been a formal evaluation by scientists of the carcinogenic risks of environmental tobacco smoke and it has concluded that it causes lung cancer,' he said.

'Environmental tobacco smoke that people experience at work or at home is definitely a cause of lung cancer.

'That has been discussed for a long time but this is the first time a group of independent scientists has reviewed all the evidence and said that there is no question.'

Sir Richard said the findings should have a significant influence on health policies and would strengthen the case for a ban on smoking in workplaces in the UK.

The IARC experts also found more types of cancer should be added to the 'already very long list' that can be caused by smoking, including cancers of the stomach, liver, uterus, cervix, kidney and myeloid leukaemia.

The group says half of all persistent cigarette smokers are eventually killed by a tobacco-related disease with half of the deaths occurring in middle age.

Tobacco is the largest cause of preventable cancers.

Sir Richard said smoking causes hundreds of cancer-causing chemicals to circulate in the body which is the reason why so many areas are vulnerable to the disease.

For example, the chemical benzene helps to trigger myeloid leukaemia. He said: 'I was personally not convinced about a link between cancer of the cervix and smoking but the evidence is now quite compelling.'

Those breathing in environmental smoke are exposed to the same chemicals as smokers, he added.

About 35,000 lung cancer deaths and a further 100,000 other deaths are attributed to tobacco in the UK each year. Around 28 per cent of adults smoke.

The group's conclusions were released at the same time as the Office of National Statistics revealed that calls to have smoking outlawed in workplaces, pubs, restaurants and public places are growing.

In 1996, 81 per cent of those questioned wanted restrictions at work but latest figures show 86 per cent now in favour.

There has also been a rise in the proportion of people wanting restrictions in restaurants - up from 85 to 87 per cent, in pubs, up from 48 to 50 per cent, and other public places, up from 82 to 85 per cent.

Although 90 per cent were aware passive smoking increases children's risk of chest infections, one-third are still prepared to smoke when in the same room as a child.

Marsha Williams, of the antitobacco campaigning group Ash, said: 'Passive smoking is quite clearly more than just the nuisance many of the world's tobacco companies would have us believe.

'People are harmed and killed by it and it is time industry, government and smokers themselves woke up to this fact.'

Around three million Britons are exposed to passive smoking in their workplaces, many of them from the hospitality industry, she said.